Mold for tires and annular articles



July 26, 193?- H. WILLSHAW ET AL 1,853,959

MOLD FOR TIRES AND ANNULAR ARTICLES Filed Dec. 2e, 195o swf@ ATToRNEYsPatented July 26, 1932 PATENT oFricE HARRY WLLSI-IAW AND THOIvI-ASNIOR'CROSS, OF ERDINGTON, BIRLIING-HAM, ENGLAND,

ASSIGNOBS TO DUNLOP TRE AND RUBBER- A CORPORATION OF NEW YEK MOLD non'rinnsnivn ANNULAR ARTICLES V'Applicationfiled December 26, 1,9?0,Serial No. 504,736, and in. Great Britain January 3, 1930.

This invention concerns improvements in or relatingto molds for tiresand annular articles and particularly relates to molds of the kindcomprising two complementary outer members each containing a recess fordetachable inserts.

The formation of semi-shells correspond ing to the articles to be moldedand made of soft metal such as tin, type metal, aluminum, or of hardmetal such as steel, is well lrnown, such shells when of soft metalbeing die cast so that the soft metal is swaged and planished, therebygiving a fine finish to theV molded article. Such shells have theadvantages of easy replacement and economy.

It has also been proposed to form a tire mold with detachable insertseach of which is flanged and attached to one of the outer members bystuds passing through the flanges into the outer members.

The object of our invention is to provide an improved mold of the kindreferred to, in which the aligning, positioning, and retaining means areof a more positive nature, being an integral part of the mold and inwhich the insertion and removal of the inserts is a quick and simpleoperation which may be effected by the insertion or the removal of onemember from each outer member for the purpose of locking the inserts intheir working positions or permitting their removal by lateraldisplacement.

Another effect of our invention is to obviate the use of ringspreviously employed either or both to position the inserts or todistribute the stress due to the suction of the article upon the insertswhen the mold is broken, whereas i'n our construction the ring is notseparately provided but is an integral mold feature which cannot bemisaligned on rfa-assembly. and therefore more accurately positions theinserts while a'dording them the maximum support against the dragconsequent upon breakin the mold.

According to this invention we provide a mold for tires and annulararticles having two complementary members. the inner surface of each ofwhich is formed with integral shoulders for positioning detachableinserts. the shoulders being discontinuous at one or -provided withseparate bead rings 3 and more places to permit the insertion or removalof the inserts by lateral displacement, and having means for completingthe continuity of the shoulders whereby the inserts N are permanentlyretained in position, the said of the mold, and in which the meansforf'@ completing the continuity of the shoulders 'positioning'theinserts consists of members carried by one of the inserts which may bemolded, cast, or die cast, with patterns or,Y designs over the whole ora part of their surfaces.

In order that our invention may be more easily understood and readilycarried into effect the same will now be described with,p reference tothe accompanying drawing, in which y i i Figs. 1 and 2 'are crosssections of tire molds;

`Fig. 8 is a part plan view to an enlarged scale of the part of the moldcontaining the insert which completes the ring and closes the slot cutin the shoulders.

Fig. i in respect of its uper half is a plan view of one of the moldsshowing the inserted molding surface 5, and the lower halfA 80 is anoutside view showing the channels permitting the circulation of theheating fluid.

rllhe mold consists oftwo separable complementary members 1 and 2 whichmay be as in Fig. 2.

' Nithin each mold member l and 2 are positioned inserts 4: and 5 whichmay be such as to mold merely the tread, or may extend downrthe sidewall as illustrated to any convenient depth.

Each outer shell is recessed to receive the .inserts which arepositioned between shoulders which are integral with the mold.

The shoulders 6 and 7 are continuous, the 95 Vinner edge of each insert-in each mold part being positioned by Contact with the respectiveshoulders 6 and 7 formed on the shells.

CORPORATION, OF BUFFALO, "NEW YORILC a second shoulder in each case, theprofile of which, eXcepting at the gap where it is cut away, follows theoutline of the integral section inserts 4 and 5 respectively between thepoints 8 to 9, and 10 to 11 respectively.

Figs. i and 2 which are cross sections through the gap show how the gapis iinally closed.

To fill each annular recess successive inserts are manipulated downwardsthrough the gap, the minimumV width of which is shown between the points13 and 14 in Fig. 3 as equivalent to the width of one insert until theintegral shoulders 8 and 10 in the mold members coincide with thecorrespond-l ing faces of the inserts whereupon the insert is slid roundin either direction. Further inserts are then inserted in successionthrough the same or similar gaps, if more than one, until by lateraldisplacement the circle of inserts is complete with the eX- ception ofthe last or key insert.

Each mold part has one key-insert for each gap. The lreyeinsert differsfrom the remainder only in being formed with or having affixed a falseshoulder 15 or 16 of the same width as the insert, which completes thecontinuity of the integral shoulders interrupted to form the gap andprovides an abutment for positioning members two in each mold half, onepair of which are shown at 17 in Fig. 3, the second pair being similarlypositioned at 18.

Having now particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed, what we claimis l. A mold for tires and annular articles havin@ two complementarymembers a number of individual inserts, the inner surface of saidcomplementary members being formed with an integral shoulder forming aninterlocking retaining groove for positioning and retaining saidinserts, the shoulder being discontinuous at one or more places to forma gap permitting inserts to be inserted and moved into engagement withsaid shoulder, and means to secure a final insert in said gap. Y

' 2. A mold for tires according to claim 1 in which the inserts extendfrom the tread to the inner periphery of the mold.

3. A mold according to claim 1, in which the means for completing thecontinuity of the shoulder positioning the inserts consists of a membercarried by one of the inserts.

4. The mold defined in claim l, in which the detachable inserts whenpositioned in said mold form a complete annular mold surface.

5. The mold defined in claim 1, in which the said inserts have a patternon their mold surfaces. Y

6. A mold for tires and annular articles having two `complementarymembers, each of said members having an annular recess and annularshoulders at the opposite edges of said recess to form retaininggrooves, inserts having back portions to fit into said recess and beretained by said shoulders, and having face portions forming an annularmold surface, the face portions of the inserts and opposite membersjoining to form a continuous mold surface, one of said shouldersbeingcut away to permit an insert to be passed therethrough and slidinto engagement in said recess, and means for retaining the final keyinsert in the cut away portion of said shoulder.

In witness whereof we have hereunto set

